Field of the Invention
The present invention relates to a side member, a cartridge, and an image forming apparatus. The image forming apparatus forms an image on a recording medium, by using an image forming process employing, for example, an electrophotographic image forming system, an electrostatic recording image forming system, a magnetic recording image forming system, or the like. Examples of the image forming apparatus include a copying machine, a printer (such as a laser beam printer and a light emitting diode (LED) printer), a facsimile machine, a multifunction peripheral having these functions, and a word processor.
The recording medium is a medium on which an image is to be formed by the image forming apparatus. Examples of the recording medium include a sheet of paper and an overhead transparency sheet. The examples also include an intermediate transfer member, and an image display member of an image display apparatus.
Description of the Related Art
For example, an electrophotographic image forming apparatus, such as a printer using an electrophotographic process, uniformly charges an electrophotographic photosensitive member serving as an image bearing member, and selectively exposes the electrophotographic photosensitive member to light. As a result, a latent image is formed. The latent image is then developed with a developer, to appear as a developer image. The developer image is then transferred to a recording medium. The developer image transferred to the recording medium is fixed by application of heat and pressure. An image is thus recorded.
For forming a color image in the electrophotographic image forming apparatus, one method is widely known. In this method, developer images (hereinafter referred to as “toner images”) formed with, for example, yellow, magenta, cyan, and black developers (hereinafter referred to as “toner”) are superimposed on one another.
Meanwhile, a cartridge system is widely adopted. In the cartridge system, a developer containing portion (a toner containing portion) containing toner and developing members such as a developing roller are incorporated into a frame, thereby forming a unit (a developing cartridge). In the cartridge system, the toner or the developing roller can be easily replaced, when reaching a predetermined lifetime.
A tandem-type color laser printer is known as an electrophotographic-type image forming apparatus. Japanese Patent Application Laid-Open No. 2007-121983 discusses an apparatus including image forming units provided in a main body casing. The image forming units are each configured of components such as a photosensitive drum, a developing portion, and a charging device. The image forming units are accommodated in a developing-cartridge accommodation tray portion shaped like a box. A user can replace the developing portion (a developing cartridge) of each of the image forming units, in a state where the tray portion (a drawer) is drawn frontward from the main body casing (an image forming apparatus main body).
In recent years, color-electrophotographic-type image forming apparatuses have been widespread, and user needs have become various. Among others, a reduction in size is expected, since the number of cases where an image forming apparatus is set on a desk and used is increasing. As the size of an apparatus main body is reduced, space for mounting a developing cartridge and a process cartridge is also reduced. Therefore, it is expected to provide a cartridge and an image forming apparatus that are small in the number of components, small in size, and low at a cost, by incorporating functions into one component, even if the space is limited.